The ionisation potential of hydrogen-atom is -13.6 eV. An electron in the groundstate of a hydrogen-atom absorbs a photon of energy 12.75 eV. How many different spectral lines can one expect when the electron make […]
Radioactivity of a sample at T₁ time is R₁ and at time T₂ is R₂. If half-life of sample is T, then in time (T₂ – T₁), the number of decayed atoms is proportional to […]
Wires A and B are made from the same material. A has twice the diameter and three times the length of B. If the elastic limits are not reached, when each is stretched by the […]
Which of the following will be σ if Y=2.4 η?
Options
(a) (-1) (b) 0.2 (c) 0.1 (d) (-0.25)
Correct Answer:
0.2
Explanation:
No explanation available. Be the first to write the explanation […]
Length of second pendulum is
Options
(a) 100 cm (b) 60 cm (c) 120 cm (d) 80 cm
Correct Answer:
100 cm
Explanation:
No explanation available. Be the first to write the explanation […]
An object is attached to the bottom of a light vertical spring and set vibrating. The maximum speed of the object is 15cm/sec and the period is 628 mili-sec. The amplitude of the motion in […]
Two discs of same material and thickness have radii 0.2 m and 0.6 m. Their moments of inertia about their axes will be in the ratio
Options
(a) 1 : 81 (b) 1 […]
A ballet dancer, dancing on smooth floor, is spinning about a vertical axis with her arms folded with an angular velocity of 20 radian/sec. When she stretches her arms fully, the spinning speed decreases to […]
A car is moving with uniform acceleration. It covers 200 m in 2 sec and 220 m in next 4 sec. The velocity of car at the end of 7th second from start is
A boy playing on the roof of a 10m high building throws a ball with a speed of 10 m/s at an angle of 30⁰ with the horizontal. How far from the throwing point will […]
2017-2025 Copyright Doctor Dreams Training Academy - About Us - Privacy Policy - Terms & Conditions - Contact Us - Refund Policy